Internal-combustion engine.



R. H. LIBKE. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JUNE 13, 1914.

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Patented Nov. 17, 1914.

,w/ rkvzssza ROBERT nnmvrnn LIBKE, or cninrc'n, w FACTURING COMPANY, or CHILTON, WI

ISCONSIN, ASSIGNOR TO ST EINER MANU- DOONSIN, A CORPORATION OFWISCONSIN.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

' Patented Nov. 17, 1914.

Application filed June 13, 1914. Serial No. 844,871.

To all whom it may concern:

Be it known that 1, ROBERT H. LIBKE, a,

citizen of the United States, and resident of Chilton, in the county of Calumet "and State of Wisconsin, have invented new and useful Improvements in Internal-Combustion Engines, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification. I v

This invention has for its object to provide an internal combustion engine with a magneto ignition mechanism havlng the magneto driven from the crank shaft at a. speed ratio of two and one-half to one.

Heretofore it has been common practlce to gear a magneto directly with the half time gear with a. pinion having half the number of gear teeth as the gear on the crank shaft, thus causing the magneto to revolve at a speed ratio of two to one w th relation to the crank shaft. Such gear ratio has been found eficient both in the normal "running operation of the engine and in the starting of the engine where the crank shaft, after having been turned a snfiicient distance in the direction of the normal running of the engine to draw into the cylinder an explosive charge, is then turned backward to cause the piston to compress the charge, and when a suitable degree of compression is attained the igniting mechanism is actuated. Although at such time this takes place in a somewhat different posii; tlon of the parts from the ordinary tion during engine running, the gear ratio of two to one causes the operation' of the ignition mechanism to take place sufficiently coincident with the attainment of the peak of the wave of currentgenerated by the magneto to resultin an eficient ignition, so that the piston is driven as inthe normal operation of the engine andthc engine s thus started. It has'been supposed that th1s gear ratio of two to one between the magneto shaft and the crank shaft is the only ,one which will give,suflicient current impulse at the proper time under ordinary starting conditions for igniting the charge and still not have the magneto acquire a speed at the full running speed of the engine that will fail to develop its maximum efficiency. I havefound that the gear ratio of two and one-half to one between the magneto shaft and the crank shaft will result in equally efii cient ignition, bothatthe starting ofthe engine and during the runnin at high speed. p

ith the above and other objectsgin view the invention consists in the internal conibustion engine as herein claimedY-and .all, equivalents. g .5)

Referring to the accompanying drawings: Figure l is a detail viev of the geardriving connection between the crank shaft and the magneto shaft of an engine constructed in accordance with this invention; and, Fig. 2 is a diagram of the alternating current produced by the magneto, showing the successive sparking points.

In these drawings 10' indicates a crank shaft carrying the crank member 11 and a. gear 12 which in the present instance contains thirty gear teeth. This gear meshes with a gear wheel 13 of twice the number of gear teeth on the cam shaft as usual, said cam shaft being provided with a cam 15 to operatethe valve rod 16in the ordinary manner. A magneto 17 -is shown as representing a magneto ignition system, without illustrating the wiring connections which are as usual, and this magneto is provided with a pinion 1S meshing with the gear wheel 13, and in this instance provided. with twelve gear teeth so that the speed ratio of the magneto shaft 19 to the crank shaft 10 is two and one-half to one. Obviously the-number of teeth in the various gear wheels may diifer from the example.

iiil'lustrated, providing the gear teeth in the gear wheel 12 are twdand one-half times the number of gear teeth in the pinion 18. *With this gear ratio of two and one-half to one the ignition, which as usual takes place with each revolution of thejcam shaft 14, occurs on the peak of every fifth wave of current generated by the magneto instead of on every fourth wave. as with the gear ratio of two t one. This is shown n the diagram of Fig, 2 at the points man-e a, 1 3 on the lower curve, while the movements of the piston are'indicated by the upper curve. the end of the inward strokeof the piston being indicated by the points 0, (Z and r" -respectivcly, from which vertical lines are dropped to the lower curve. It will thus be seen that ignition takes place during ordinary running at the peak of a wave of current generated by the magneto while the crank is nearing the end of its compression stroke.

d On startmg'the engine the piston is moved through its intake stroke from the point 0? to a point f so as to draw in a charge of explosive mixture, and is then backed toward the point (1 and ignition is produced at the point g, before the piston has reached the end ofits inward stroke. The compressed charge is thus exploded and the engine starts 'in its normal operation. The speed of the magneto on starting the engine is somewhat greater than with an engine with the gear ratio of two to one, and the peak of the current wave is produced at a point favorable to the attainment of proper com,- pression so that starting is easily accomplished. When the engine is running at full speed the speed of the magneto is not excessive and it develops its maximum efliuency.

What I claim as new and desire to secure by Letters Patent is:

1. In an interna combustion engine, a magneto ignition ystem having the magneto geared with the-crank shaft at a speed ratio of two and one-half to one.

2. In an internal combustion engine, a crank shaft, a half speed gear driven thereby, and a magneto ignition system with the magneto geared to the half time gear at a speed ratio of two and one-half to one with relation to the crank shaft.

In testimony whereof, I affix my signature, in presence of two witnesses.

ROBERT HERMAN LIBKE.

Witnesses:

A. C. KINGSTON, H. J. SGHOMMER. 

